硫酸铵焙烧粉煤灰的熟料溶出动力学研究

对硫酸铵焙烧粉煤灰的熟料溶出过程进行了动力学研究,根据不同温度、不同搅拌强度、不同液固比中Al2O3的溶出率和反应时间的关系,计算该反应的表观活化能为19.93 kJ/mol,熟料的溶出过程受通过固体产物层的内扩散控制,动力学方程为:1+2(1-x)-3(1-x)2/3=4.52exp{-19929/RT}·t。在液固比8:1,溶出温度为90℃,搅拌强度为300 r/min,溶出时间70 min的条件下,Al2O3的溶出率可达84%。     

红土镍矿焙烧熟料溶出过程中镍的行为

以红土镍矿-硫酸铵混合焙烧后所得熟料为研究对象,采用水溶出的方法提取镍,系统地研究溶出温度、液固比、溶出时间、搅拌强度对镍溶出率的影响,并对镍的溶出动力学进行探讨。结果表明:在最优溶出条件下:溶出温度60℃,溶出时间60 min,液固比2.5:1,搅拌强度400 r/min时,镍的溶出率达到99%以上;镍的溶出反应受外扩散控速,根据阿伦尼乌斯经验方程计算得到反应的表观活化能为E=8.08 kJ·mol,得到溶出过程动力学方程为1-(1-α)2/3=0.2749exp(-8075/RT)t。     

硫酸铵焙烧钛渣提钛的研究

通过单因素试验,研究了焙烧温度、硫酸铵与钛渣质量比、原料粒度和焙烧时间对二氧化钛提取率的影响。正交试验结果表明试验过程中各因素对二氧化钛提取率的影响由大到小的顺序为:焙烧温度焙烧时间硫酸铵与钛渣质量比。得到最佳试验条件,即在硫酸铵与钛渣质量比为5∶1、焙烧温度为470℃、钛渣粒度为44~49μm,焙烧时间为80 min时,钛渣中二氧化钛的提取率可达到80%。     

红土镍矿-硫酸铵焙烧熟料铁溶出动力学

以红土镍矿-硫酸铵混合焙烧后所得熟料为研究对象,采用水溶出的方法提取铁,系统地研究溶出温度、液固比、溶出时间、搅拌强度对铁溶出率的影响,并对铁的溶出动力学进行探讨。结果表明:在溶出温度60 ℃、溶出时间60 min、液固比2.5 GA6FA 1、搅拌强度400 r·min-1的条件下溶出时,铁的溶出率可达到99%以上;动力学分析表明,铁的溶出反应受外扩散控制,根据阿伦尼乌斯经验方程计算得到反应的表观活化能为E=7.23 kJ·mol-1,得到溶出过程动力学方程为1-（1-α）2/3=0.208 5 exp（-7 234/RT）t。      

钛渣硫酸铵焙烧法提钛渣提硅试验研究

采用硫酸铵焙烧法从钛渣中提钛后得到大量的滤渣,主要含有二氧化硅和氧化钙。将滤渣和氢氧化钠溶液混合均匀加热搅拌,抽滤后得到硅酸钠溶液,最佳工艺条件:NaOH与滤渣质量比3.5︰1、反应温度210℃、液固比5:1、反应时间80 min;将硅酸钠溶液加入氧化钙加热搅拌,在110℃时反应60 min过滤分离,得到硅酸钙沉淀,同时得到氢氧化钠溶液。     

氟化钾助溶法对粉煤灰中氧化铝溶出率的影响研究

针对传统工艺从煤粉炉粉煤灰中提取氧化铝提取率低的问题,采用了以KF·2H2O为焙烧助溶剂的方法,从粉煤灰中酸溶氧化铝,粉煤灰中氧化铝的溶出率可达95%以上。研究了焙烧配比、焙烧温度、溶出固液比、溶出温度、溶出时间等对粉煤灰中氧化铝溶出率的影响,并用XRD对烧结样品和酸浸渣进行了表征。研究结果表明,氟化钾助溶法对煤粉炉粉煤灰中的氧化铝活化效果明显,活化后主要相态为霞石,在焙烧配比为20∶19、焙烧温度为900℃、焙烧时间为1 h的最佳活化条件下及6 mol/L HCl、1/4的固液比、60℃溶出30 min的最佳溶出条件下,粉煤灰中氧化铝的溶出率达97%以上,且氟最终主要在酸浸渣里。     

电解锰渣碱浸提硅工艺及动力学研究

研究了电解锰渣碱浸提硅过程中, 浸出时间、浸出温度、氢氧化钠初始浓度、液固比(溶液体积与电解锰渣质量比)和搅拌速率对二氧化硅浸出率的影响, 探讨了电解锰渣中二氧化硅的浸出动力学。结果表明, 当浸出温度130 ℃、浸出时间5 h、氢氧化钠初始浓度12.5 mol/L、液固比5 mL/g、搅拌速率300 r/min时, 二氧化硅浸出率达到82.04%; 90~130 ℃时, 浸出过程遵循受界面化学反应控制的收缩未反应核模型, 化学反应活化能为72.0 kJ/mol, 表观反应级数为1.12。     

以硫化钙为还原剂焙烧还原提取锰除尘灰中的锰

研究了以硫化钙为还原剂焙烧还原提取锰除尘灰中的锰, 考察了焙烧时间、焙烧温度、物料配比、搅拌速率、浸出温度、液固比、浸出时间和H₂SO₄浓度对锰除尘灰中锰及铁浸出率的影响。结果显示, 焙烧还原工艺最佳条件为：锰除尘灰与还原剂硫化钙质量比4.12∶1、焙烧还原温度600 ℃、焙烧还原时间1.0 h, 酸浸工艺最佳条件为：搅拌速率300 r/min、H₂SO₄浓度3 mol/L、液固比8∶1、浸出温度80 ℃、浸出时间25 min, 最佳工艺条件下锰、铁浸出率分别为98.18%和76.83%。     

反应条件对煤系高岭土脱硅率的影响

利用氢氧化钠溶出脱硅法研究了搅拌速度、NaOH浓度、反应温度、反应时间、液固比和助剂这些溶出条件对煤系高岭土脱硅率的影响,并进一步考察了两段溶出对煤系高岭土脱硅率的影响。试验结果表明,煤系高岭土在搅拌速度为900r／min、NaOH浓度为150g／l、加硅类助剂、90℃脱硅处理90min、液固比大于5ml／g的溶出条件下,可获得较高的脱硅率,从而极大地提高A／S比值;两段溶出亦可提高煤系高岭土的脱硅速率与脱硅率,也使铝损失量和A／S比有所增加,     

湿法处理钠硅渣回收氧化铝工艺研究

对钠硅渣脱碱后的水化石榴石通入CO₂气体转型的反应进行了热力学分析, 研究了温度、时间、改性次数、Na₂CO₃浓度对转型效果的影响, 并且研究了转型后渣溶铝过程中, 苛性碱浓度、温度、液固比、反应时间对氧化铝溶出率的影响。结果表明: 钠硅渣脱碱后形成的水化石榴石能被CO₂分解, 在分解过程中硅化合物易形成CaO·SiO₂·H₂O、6CaO·6SiO₂·H₂O。反应时间的延长, 适当的反应温度, 有利于提高水化石榴石的转化率, 同时改性处理也可以提高转化率。在溶铝过程中, 时间延长, 液固比提高, 碱浓度升高, 以及适宜的反应温度均可提高溶铝效率。试验最佳工艺条件为: 转型最佳工艺为时间2 h, 液固比5～10, 温度50 ℃, 改性一次; 溶铝最佳工艺为温度50 ℃, 液固比为10, 时间1 h, 碱浓度大于50 g/L, 最优条件下氧化铝溶出率达60%以上, 弃渣中铝硅比A/S小于0.6。     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared     

矿用防爆轴流对旋主要通风机叶片ANSYS模态分析及应用

高效节能矿用防爆对旋主要通风机的叶片是主要通风机运行的关键部件,叶片在运行时不断受到气流的作用力,从而使叶片产生振动,当叶片振动的频率与叶片的固有频率接近时,容易产生共振从而导致叶片的断裂。一旦叶片断裂时,对主要通风机的安全运行产生致命的影响,从而导致矿山、化工等企业发生重大事故,将会产生不可估量的损失。基于有限元分析软件ANSYS,对高效节能矿用防爆轴流对旋主要通风机叶片进行模态分析及产生对应的六阶模态频率,对主要通风机叶片的运行频率、固有频率及产生的共振问题进行了原理分析,并且解决了叶片频率共振的问题,从而为主要通风机叶片结构设计提供理论依据,并对主要通风机叶片的安全运行提供保障。     

2013 NdFeB export analysis

<正>China totally exported nearly 24,000 tonsof NdFeB products during 201 3,including 18,825 tons of permanent magnet,valued USD 1.34 billion at an average price of 71.4 USD/kg;3,277 tons of NdFeB magnetic powder,valued USD 1 01 million at an average price of 30.9 USD/kg;1,334 tons of strip casting ribbon,with total export value of USD 74million at an average price of 55.3 USD/kg;and 586     

Market and recycling of NiMH battery

<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH     

China rare earth market review

正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to     

唐口煤矿深部复杂开采工作面瓦斯分源涌出规律研究

研究工作面瓦斯涌出规律对工作面瓦斯治理有重要意义。为了得到唐口煤矿深部3号煤层复杂开采条件下工作面回采时期瓦斯涌出时空演化规律,选取6304工作面作为对象,采用实测方法研究6304工作面瓦斯涌出规律。结果表明:6304工作面瓦斯涌出量为6.534 m³/min,其中煤壁占34.27%,落煤占29.62%,采空区占36.11%;沿工作面倾向由低到高,瓦斯浓度整体为上升趋势,其中1—76号架工作面瓦斯浓度小于0.20%,76—102号架瓦斯浓度上升明显,最大为0.387%;上隅角的后部采空区是工作面的瓦斯主要涌出源,上隅角1号测点瓦斯浓度0.78%,上隅角周边3号、5号、7号、8号、9号测点瓦斯浓度平均为0.643%;周期来压时,上隅角瓦斯相对平时较高。研究为针对性的瓦斯分源监控与灾害防治提供基础。